Copy/insert a row to a position defined in a form

Hi, I'm not an experienced VBA programmer, so hopefully (and probably) for you it's easy to tell me how to do it:

So far, I copy a row(1) to another position (7) with this macro:

Rows("1:1").Select
Selection.Copy
Range("A7:BU7").Select
Selection.Insert Shift:=xlDown
Range("A7:BU7").Select
Application.CutCopyMode = False
Range("A7").Select

That works well so far.
Now what I want to do is, to use a form and enter a number and have the row 1 inserted in this row number (because it should not always be in row 7). For example that i can insert 38 in the form and it will copy the row number 1 to row number 38.

I tried this
Range("frm_insertrow.txt_rownumber").Select

Which you're probably laughing at now

I hope somebody can help me, thanks!